Iron deficiency anemia (IDA) affects an estimated one billion people worldwide. In children, IDA has been linked to a number of cognitive, behavioral, and motor problems. There is a need for an early predictor of iron status (IS) that would allow for treatment prior to the onset of IDA. Hemoglobin (Hgb) is the standard measure of IS obtained during an infant’s postnatal visits. However, Hgb is late indicator of IS. Zinc protoporphyrin/heme (ZnPP/H) ratios can provide an early and cost effective measure of IS, utilizing only 20 microliters of blood. Mother-raised rhesus monkey (Macaca mulatta) infants have also been shown to go through a period of ID prior to, or shortly after, weaning. Therefore, we investigated the predictive relationship of various iron indices (ferritin, ZnPP/H, Hgb, and mean corpuscular volume (MCV)), along with body weights, on the 6-month IS of 43 rhesus infants. Hierarchical linear regression analyses indicated that early growth, from birth to 2 months [β=-0.274, p<0.05], and ZnPP/H at 2 months [β=-0.439, p<0.01], were predictive of MCV at 6 months of age. Infants who grow rapidly are at risk of depleting the iron stores they are born with, if not supplemented. Rhesus monkey infants at risk for IDA can be identified early by monitoring growth, and obtaining ZnPP/H ratios. This strategy could likely be applied to human infants (Homo sapiens)as well.